The Hile Alabama Blog

A blog dedicated to process control, industrial instrumentation and measurement & control. Weekly posts highlighting educational, informative, and new product information on all aspects of process control equipment. Courtesy of Hile Alabama | Call us at 205.620.4000

Friday, May 24, 2019

The Coriolis patents for industrial application were filed back in the 1950s, and the first Coriolis flowmeter was introduced in the 1970s. Coriolis flowmeters can accurately measure the density, mass flow, volumetric flow, and temperature of almost all types of fluids.

Coriolis flowmeters are used in a variety of industries ranging from oil and gas, petrochemicals, and food to chemical, life sciences, and — particularly — in transfer applications.

How Does a Coriolis Flow Meter Work?

Coriolis flowmeters work on the principle of Coriolis Force that was first explained by a French engineer and mathematician Gaspard-Gustave de Coriolis in the 19th century. The Coriolis force represents an inertial force that acts on bodies in a rotating frame of reference.

Also known as inertial mass flowmeters, Coriolis flowmeters measure fluid flow through inertia. The device has one or more measuring tubes that vibrate due to the force produced by an actuator. The twisting force inside the measuring tube is directly proportional to the mass flow of the liquid.

Coriolis meters have sensors inside the measuring flow tube made of magnet and coil assemblies. The sensors are located both at the inlet and outlet of the tube. A voltage in the form a sine wave is created as the coils move through the magnetic field.

The sine waves are in phase with each other when there is no liquid flow. Once the liquid flows through the tube, the measuring tubes twist depending on the mass flow. The sensors detect the extent of the twist by assessing the phase shift in the sine waves. The difference in phase shift helps in determining the mass flow rate.

Volumetric flow is determined by dividing the mass flow rate by the density of the liquid.

Density change is determined by assessing the change in oscillation frequency in response to the excitation inside the tube. The higher the mass flow rate, the lower will be the frequency change and density of the liquid flow.

Lastly, Coriolis flowmeters can also be used to measure the temperature inside the tube. The device has sensors inside the tube that can detect temperatures of up to 752 F or 400 C.

The Pros and Cons of Coriolis Flow Meters

Coriolis flow meters can assess liquid flow in both forward and reverse directions. Advanced Coriolis meters have dual curved tubes that can measure with more accuracy. Moreover, the device with curved tubes is characterized by lower pressure drop, making them ideal in specific situations such as wastewater handling, chemical processing, pulp and paper processing, and oil and gas industries.

Another application of Coriolis flow meters is in the pharmaceuticals and food and beverage industries. They can be used with a straight tube design so they are easy to clean. The flowmeters are also used in scientific studies for measuring corrosion and assessing liquids and gases. In addition, the flowmeters are used in mining operations to monitor liquid flow rate.

While Coriolis meters allow accurate assessment of fluid flow, they are not free from errors. The
device can show inaccurate reading when air bubbles are present. The bubbles create splashing that results in generate inaccurate readings. They change the energy required for tube oscillation, resulting in a false assessment of fluid flow.

A lot of energy is spent in the vibration of the tube, especially in case of large spaces. This can also result in failure of accurate assessment of liquid flow inside the tube.

Installation and Calibration of Coriolis Flow Meter

Coriolis flowmeter must be installed with full liquid so that no air gets trapped inside the tube. The meter should also be drained completely before use. The ideal location for the flowmeter is a vertical pipe mount with an upward flow of fluid.

The Reynolds number is not a limitation with the Coriolis meter. In addition, there is no need for accounting for swirl and velocity profile distortion. As a result, the device can be used without adjusting for straight runs of relaxation piping to condition the liquid flow.

An air release upstream of the meter should be installed if there is a likelihood of air bubbles. In addition, filters, strainers, or air/vapor eliminators can help prevent air bubbles inside the tube. Control valves can also be installed to increase the back-pressure and reduce the likelihood of flashing.

Thursday, April 25, 2019

With fast and reliable settings, ABB's LWT300 series of instruments emphasizes measurement made easy. With its LevelExpert technology based on 20 years of experience, simply enter installation data and basic process conditions, and let LevelExpert do the rest: no echo mapping or baseline correction required.

Unlike traditional guided-wave radars that use device parameters requiring multiple adjustments, the LWT300 series of instruments does it for you. The instrument uses built-in intelligence to differentiate between the actual level and other false signals. It also keeps monitoring all these false signals while maintaining a reliable level reading. It is like having a level expert in each device.

Saturday, April 20, 2019

The ABB LWT Series is a family of guided wave radar transmitters utilizing the most advanced level algorithm, LevelExpert. With LevelExpert, you no longer need to be an instrument expert to accurately control level. With the LWT Series, the expert is inside.

Main Features:

To meet the most challenging level applications, the LWT300 series of instruments offers a wide range of configurations.

Saturday, March 23, 2019

White paper courtesy of Eurotherm Schneider Electric.
Traditionally, three-leg power control is used in three phase heating applications. However, in some cases three-leg control is not a necessity and two-leg control can be a better option. Technological developments in SCR (silicon controlled rectifier) power controllers have resulted in new products and methods that can reduce both CAPEX and OPEX in these situations.

This paper discusses the benefits of utilizing two-leg power control in the EPower advanced SCR power controller, compared with traditional three-leg control.

Wednesday, March 13, 2019

IN-FLOW Mass Flow Meters and Controllers up to pressure rating 400 bar (5800 psi) are now available with FM approval for Class I, Division 2, for the North American market. These MFCs are available with a rugged IP65 (dust - and waterproof) construction and an optional ATEX approval for use in Category 3, Zone 2 hazardous areas.

Additionally, Bronkhorst is now offering a PROFINET fieldbus interface on their industrial mass flow meters and controllers for gases (FM and ATEX approvals pending). PROFINET is looked at as the new standard for industrial automation, offering major savings in configuration and commissioning.

The flexible architecture of PROFINET, with its comprehensive scope of functions, enables innovative, flexible, and cost-saving machine automation provides:

Thursday, February 28, 2019

The AutrolAPT 3500 Smart Pressure Transmitter is a microprocessor-based high-performance transmitter, which has flexible pressure calibration and output, automatic compensation of ambient temperature and process variable, a configuration of various parameters, communication with HART protocol. The application is very various, as measuring liquid, gas or steam flow as well as pressure and liquid level by an application method. All data of the sensor is to be input, modified and stored in EEPROM.

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About Hile Alabama

Hile Controls of Alabama, Inc. is an independent manufacturer's representative firm, representing the finest instrumentation available for the territory of Alabama, Mississippi, and the Florida Panhandle. We provide controls, instrumentation and valves for manufacturers in oil and gas, chemical production, power generation, plastics, mining, water and waste water, pharmaceuticals and bio-pharmaceuticals, food and beverage, pulp and paper, and government-related industrial manufacturers.

Our engineering expertise and ability to analyze and develop a solution for the application in question is second to none.